Acrylic or methacrylic terminated oligomers

ABSTRACT

Acrylic or methacrylic terminated unsaturated maleate or fumarate oligomers are disclosed. The oligomers can be reacted with other ethylenically unsaturated compounds through the acrylate, methacrylate, or maleate/fumarate functionality, they can also be reacted with amines through Michael addition to the acrylic or maleate unsaturation with or without a post reaction through the methacrylate functionality.

This is a division of application Ser. No. 373,372 filed Apr. 30, 1982,now U.S. Pat. No. 4,463,150.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to acrylic and methacrylic terminatedmaleate/fumarate oligomers which are especially useful as thermosettingresins which are crosslinked with amines.

2. Description of Prior Art

Japanese patent application KO No. 73-32818 of Ito et al of Toa GoseiChemical Industry Co. Ltd. discloses the reaction product of an alpha,beta-unsaturated carboxylic acid/polybasic acid anhydride/epoxy compoundin the mol. ratio of 1:0.5-1.0:1-20 to produce esters having acryloxygroup or methacryloxy group as the terminal group on one end of themolecule and hydroxyl group or carboxylic acid on the other end.Compounds having at least two maleic unsaturation sites per acrylic ormethacrylic unsaturation site are not disclosed.

Japanese Pat. No. 71-18,965 appears to be cumulative to theabove-referenced Japanese patent publication. In Example 1 of thispatent, the reaction product of acrylic acid, maleic anhydride, andethylene oxide in a molar ratio of 1:1:2 is disclosed.

Ilenda, U.S. Pat. No. 4,180,632, shows polymers of acrylic acid monomershaving an average acrylate functionality of at least 2.5 reacted withlow molecular weight aliphatic amines to form polyamino esters. TheIlenda system is used for Reactive Injection Molding (RIM).

SUMMARY OF THE INVENTION

It is an object of the present invention to provide new acrylate andmethacrylate functional compounds which are especially useful forreaction with amines in a RIM system.

Another object is to provide very versatile methacrylate functionaloligomers which can be reacted through a maleate functionality whileleaving the methacrylate functionality unchanged.

A further object is to provide soluble postreactive prepolymers orinsoluble postcurable thermosetting resins of improved properties.

A still further object is to provide novel resins for coatings, textileprinting and dyeing, casting, polymeric modifiers, elastomericcompounds, sealants, adhesives, and the like.

These objects, and others which will become apparent from the followingdisclosure, are achieved by the present invention which comprisescompositions comprising a compound of the formula ##STR1## wherein n isgreater than or equal to 2; R=--H, --CH₃, --C₂ H₅ ;

R', R"=--H, --CH₃, --C₂ H₅, --CH₂ Cl, --CH₂ --Br, --C₆ H₅, --CH₂OCOCH═CH₂, --CH₂ OCOC(CH₃)═CH₂, --CH₂ OCH₂ CH═CH₂, --CH₂ OC₆ H₅, --CH₂OC₄ H₉, or R' and R" form a cyclic ring --C₄ H₈ --.

R"'=--H or --CHR'--CHR"--OH or C₂ H₄ OH.

In another aspect the invention comprises preparing compounds of formulaI comprising reacting an initiator of the formula ##STR2## wherein R,R', and R" are as previously defined and m=0 or 1, with maleicanhydride, an epoxide, and a catalyst in mole ratios of at least 2 molesof maleic anhydride and, depending on the nature of m and R"', at least1 to 3 moles epoxide per mole of initiator.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS

The oligomers of formula I are prepared, preferably, by reacting acompound of formula II with maleic anhydride and an epoxy compound suchas ethylene oxide in mole ratios of 2 to 4 moles maleic anhydride and 1to 5 moles, preferably 3 to 5, epoxy compound per mole of compounddepending on whether the compound is the acid or hydroxyethyl ester andon whether the terminal group on the other and of the molecule is to beacid or ester.

The compound, which provides the (meth)acrylate functionality to theresultant oligomers, can be acrylic acid, methacrylic acid, or2-hydroxyalkyl methacrylate such as hydroxyethyl methacrylate (HEMA)with the latter being preferred.

A wide variety of catalysts can be employed, usually about 0.1 to 2.0%,with the preferred catalyst being quaternary ammonium salts, calcium,magnesium and lithium halides, and tertiary amines. Specific examples ofsuitable catalysts are tetramethylammonium bromide, tetramethylammoniumchloride, tetramethylammonium methyl sulfate, lithium chloride orbromide. The preferred catalysts promote the reaction between anhydrideand epoxide with little or no homopolymerization of the epoxide.

The unsaturated acrylate or methacrylate monomer can be acrylic acid,methacrylic acid, 2-hydroxyalkyl acrylate, or 2-hydroxyethylmethacrylate. Other monomers can be substituted in part or completelyfor the acrylic or methacrylic monomer; for example, crotonic, itaconic,citraconic, alpha-methylene glutaric acid, and the like.

A minor amount of the maleic anhydride can be replaced by othercarboxylic acid anhydrides such as phthalic, succinic,tetrahydrophthalic, hexahydrophthalic, itaconic, mellitic, and the like.

Epxoides which can be used are ethylene propylene, butylene, isobutyleneand styrene oxides, epichlorohydrin, glycidyl acrylate or methacrylate,epibromohydrin, allyl glycidyl ether, phenylglycidyl ether, butylglycidyl ether, cyclohexene oxide, or mixtures of such epoxides.

The aforementioned molar ratios are an important feature of the presentinvention because of the intended utility as reactants with polyaminesin the RIM process to produce thermosetting resins. At least two andpreferably three or more maleate functional groups are required forreaction with polyamines for this purpose. Some maleate can beisomerized to fumarate as long as at least 2 maleates per moleculeremain.

The alkylene oxide mole ratio is kept near the available carboxylic acidratio or one mole deficit depending on whether the ester or acidterminal group is desired.

The reaction is conducted at a temperature of about 50° to 120° C. andmore preferably 70° to 105° C., by introducing the raw materials all atonce or preferably by adding the acid or hydroxyalkyl ester of the acidcompound to the molten maleic anhydride and any other anhydride, andthen adding the epoxy compound at a controlled rate to complete thepolymerization.

The reaction can be conducted in the absence or the presence of asolvent such as benzene, toluene, and the like.

Polymerization inhibitors such as hydroquinone, hydroquinone monomethylether, phenothiazine, copper powder, and the like can be employed.

The oligomers of the invention can be reacted with polyamines to formthermosetting resins. If the initiating acid is methacrylic, suchfunctionality is very slow to react with amine and is available for afacilitated postcure reaction with normal peroxide free radicalinitiation. In addition, methacrylic (or acrylic) functionality greatlyincreases the possibility for copolymerization with a much wider rangeof comonomers than does residual maleate functionality.

Certain of the oligomers of the invention, especially methacrylicterminal groups, react with certain diamines to give solublenoncrosslinked polymers. Such materials are reactive prepolymers capableof further incorporation in acrylic polymer systems.

A third option is reaction of these maleate oligomers with monoamines toreadily form a class of polymerizable polyamines.

The following non-limiting examples are presented to illustrate a fewembodiments of the invention.

EXAMPLE 1

To molten maleic anhydride (196 parts) containing p-methoxyphenol (0.17parts) was added with stirring at 60°-80° C., 2-hydroxyethylmethacrylate (130 parts) in 3 aliquots over a period of 1.5 hours. Themixture was heated an additional 2 hours at 80° C. and swept with N₂.Ethylene oxide (97 parts) was then bubbled in with stirring in thepresence of tetramethyl ammonium bromide (0.83 parts) catalyst over a7-hour period at 85°-95° C. and a maximum pressure of 10 psig. The batchwas vacuum stripped at 50°-60° C. and 30 mm Hg pressure. The strippedresidue amounted to 428 grams (calc. 414) for a conversion of 103%.Residual acidity 11.2 A.N. The product was an amber color liquid with aviscosity (neat) of 880 cps. at 25° C. Unsaturation by Br. No. was 93%of theory (108 ctg/gm.-calc. 115.8). The maleate/fumarate ratios haveshown 90% maleate functionality. The product was essentially ##STR3##

EXAMPLE 2

Following the procedure of Ex. 1, ##STR4## was prepared from maleicanhydride (294 parts), p-methoxyphenol (0.22 parts), 2-hydroxyethylmethacrylate (130 parts), tetramethylammonium bromide (1.11 parts), andethylene oxide (153 parts) in an 11-hour reaction period at 95°-100° C.The final acidity was A.N. 0.4, and conversion was 102%. An 80% solutionin styrene showed a viscosity of 200 cps. at 25° C.

EXAMPLE 3

The acid terminated monomer ##STR5## was prepared by heating the productof Example 1 (103.5 parts) with maleic anhydride (24.5 parts) withstirring at 100° C. for 4 hours in the presence of p-methoxyphenol (0.05parts). Acid No. found 102.7; calc. 100.6 for this particular ratio ofreactants.

EXAMPLE 4

Methacrylate terminated polyethylene maleate as prepared in Example 2was mixed with 0.2% by weight of free radical initiator di-tert-butylperoxide. The mixture was heated to 80° C. for 0.5 hour, 110° C. for 0.5hour, 140° C. for 0.5 hour, and 170° C. for 1 hour to produce a hard,clear, amber polymer.

EXAMPLE 5

Following the procedure of Example 1, ##STR6## is prepared from 196parts maleic anhydride, 144 parts hydroxypropyl methacrylate, and 128parts propylene oxide.

EXAMPLE 6

A mixture of 265 parts molten maleic anhydride, 30 parts succinicanhydride, and 86 parts crotonic acid is swept with nitrogen. Gradually193 parts ethylene oxide are added in the presence of 1.7 partstetramethyl ammonium chloride and 0.29 parts p-methoxyphenol over a 12hour period at 85°-100° C. and a maximum pressure of 20 psig. to form##STR7##

EXAMPLE 7

Following the procedure of Example 1, ##STR8## is prepared from 196parts maleic anhydride, 116 parts of 2-hydroxyethyl acrylate, and 97parts ethylene oxide in the presence of 0.83 parts tetramethyl ammoniumbromide, 0.20 parts p-methoxyphenol, and 0.20 parts quinone.

EXAMPLE 8

Methacrylate terminated polyethylene maleate (wherein n=2 R=--CH₃, R'and R"=--H, and R"'=--C₂ H₄ OH) (40 parts) was mixed with styrene (10parts) containing ditert-butyl peroxide (0.1 part) and benzoyl peroxide(0.08 parts). The mixture was heated to 80° C. for 1.5 hours, 140°C.-1.5 hours, and 170° C.-1.5 hours to form a hard, clear, pale ambercolored polymer.

What is claimed is:
 1. An oligomer comprising the formula: ##STR9##wherein n is greater than or equal to 2; R=--H, --CH₃, or --C₂ H₅ ;R',R"=--H, --CH₃, --C₂ H₅, --CH₂ Cl, --CH₂ Br, --C₆ H₅,--CH₂ OCOCH═CH₂,--CH₂ OCOC(CH₃)═CH₂, --CH₂ OCH₂ CH═CH₂, --CH₂ OC₆ H₅, or --CH₂ OC₄ H₉,or R' plus R" form a cyclic ring --C₄ H₈ --; and R"'=--H or --C₂ H₄ OH.2. The oligomer of claim 1 wherein R, R' and R" are each --H, R"' is --Hor --C₂ H₄ OH, and n=2 to
 4. 3. The oligomer of claim 1 wherein R=--CH₃,and R' and R" are each --H, R"' is H or --C₂ H₄ OH, and n=2 to 4.